Nonvolatile memories, such as NAND flash memories, are widely used for high-capacity data storage in cellular phones, digital still cameras, USB (Universal Serial Bus) memories, silicon audio players and the like. Furthermore, novel applications have also been fast emerging, causing demand for downscaling and manufacturing cost reduction thereof. In particular, in a NAND flash memory, a plurality of active areas (A.A.) share a gate conductor (G.C.), thereby effectively realizing cross-point cells. Because of its simple structure, rapid downscaling and manufacturing cost reduction are in progress. However, a NAND flash memory is based on the operation of a transistor which records information using its threshold variation, and reportedly has limitations on further improvement in characteristics uniformity, reliability, operating speed, and integration density.
In this context, for instance, phase change memory elements and resistance change memory elements are based on the variable resistance state of resistance materials, and hence need no transistor operation in the write/erase operation. Thus, further improvement is expected in characteristics uniformity, reliability, operating speed, and integration density.